Acacia from the Greek 'akakia' and derived from 'ake' or 'akis' meaning a sharp point or thorn and 'akazo' meaning to sharpen. Dioscorides, the Greek physician and botanist used the word in the 1st century AD for the Egyptian thorn tree, Acacia arabica. Araneosa from the Latin 'araneosus' meaning cobweb-like, referring to the cobwebby appearance of the tree due to the mesh of long fine branches and leaves.

Distribution:

Endemic to South Australia. Found on hillsides and ridges and restricted to a small area in the Flinders Ranges region (northern part) from Nudlamutana Well near Balcanoona along the ranges to Arkaroola.

Status:

Native. Very rare in South Australia.

Plant description:

Small, erect, wispy trees to 8 m high, with a cobwebby in appearance. Bark smooth, grey but becoming reddish-brown on young branches. Leaves slender, glabrous, light green to 35 cm or sometimes to 69 cm long and to 1.8 mm diameter with curved tips. Small gland situated near leaf base. Inflorescences axillary racemes with globular, yellow flower-heads. Flowers irregular periods throughout the year.

Fruit type:

Long brown, slightly curved pods to 15 cm long and 6 mm wide, with prominent vein-like margins and constricted between the seeds.

Seed type:

Hard black ovoid seeds to 5 mm long and 3 mm wide with a long orange aril.

Place the pods in a tray and leave to dry for 1-2 weeks or until the pods begin to split. Then rub the dried pods to dislodge the seeds. Use a sieve to separate any unwanted material. Store the seeds with a desiccant such as dried silica beads or dry rice, in an air tight container in a cool and dry place.

Seed viability:

From one collection, the seed viability was high, at 100%.

Seed germination:

This species has physical dormancy that needs to be overcome for the seed to germinate (e.g. nicking or softening the seed coat).

Seeds stored:

Location

No. of seeds(weight grams)

Numberof plants

Datecollected

Collection numberCollection location

Datestored

% Viability

Storagetemperature

BGA MSB

990 (15.88 g)990 (15.88 g)

50+

24-Nov-2005

DJD227Flinders Ranges

1-Aug-2006

100%

-18°C

Location: BGA — the seeds are stored at the Adelaide Botanic Gardens, MSB — the seeds are stored at the Millennium Seed Bank, Kew, England.Number of plants: This is the number of plants from which the seeds were collected.Collection location: The Herbarium of South Australia's region name.% Viability: Percentage of filled healthy seeds determined by a cut test or x-ray.